By Deena Beasley

LOS ANGELES (Reuters) - Obesity exacts a higher toll on health and healthcare costs than either smoking or drinking as serious obesity-related problems like diabetes are near epidemic levels, according to a study released on Tuesday.

"Smoking and drinking, which are on the decline, have been the focus of research and policy work for years. Yet obesity, which can have far more serious health consequences, has received far less interest" said Roland Sturm, author of the study and a researcher at the UCLA/RAND Managed Care Center for Psychiatric Disorders in Santa Monica, California.

The study found that obesity -- linked to health complications including diabetes, arthritis, heart disease, strokes and certain cancers -- raises a person's healthcare costs by 36 percent and medication costs by 77 percent.

Smoking and drinking also cause serious health problems, but the study, released by the journal Health Affairs, found that active smoking leads to a more modest 21-percent rise in healthcare costs and 28-percent increase in medication costs, with smaller effects seen for problem drinkers.

"Obesity is associated with a lot of chronic conditions, which have a large impact on health costs. Diabetes needs constant care," Sturm said. Diabetes, a condition in which the body's ability to process sugar is impaired, raises the risk of kidney failure, blindness, heart disease and circulatory problems that can force amputations.

Sturm cited more and more hours in front of the television, less physical activity and a car-obsessed culture, as significant causes of American's growing obesity problem.

The U.S. Surgeon General in a December report placed the blame on diet and urged people to cut back on sugar and fats. The recommendation was criticized by the Sugar Association, which thought the report should have stressed fitness more.

The RAND study, based on a 1998 U.S. household telephone survey of about 10,000 adults, found that people who are obese have 30 percent to 50 percent more chronic medical problems than smokers or problem drinkers.

Health experts have said the number of diabetes cases in the U.S. could nearly double over the next 50 years as a population fond of junk food and prone to obesity ages.

Obesity rates in the United States nearly doubled in the 1990s -- from around 12 percent in 1990 to 23 percent in 1998, when the study was conducted. In comparison, daily smokers made up 19 percent of the population and 6 percent were classified as heavy drinkers.

The recent Surgeon General's report said 27 percent of Americans are obese, and 61 percent are overweight.

People with a body mass index -- a measure of weight in relation to height -- of more than 30 are considered to be obese. For example, somebody who is 5 feet 8 inches tall and weighs 197 pounds or more.

In terms of dollar amounts, the study found that obesity raised healthcare costs by an average of $395 a year, while smoking increased costs by $230 and heavy drinking is associated with a $150 annual increase.

Sturm said higher taxes on cigarettes have played a big role in deterring people from smoking, but a similar approach to weight control -- the so-called "twinkie tax" -- is unlikely to work.

"I don't think McDonald's is making people obese. We need to have more of a public health angle, not just doctors telling people to lose weight," Sturm said.